Live from NPR News in Washington, I'm Dave Mattingly.

Millions of people across the U.S. are bracing for a major winter storm.

The National Weather Service has issued winter storm warnings from New Mexico to New England.

Heavy snow, sleet, and freezing rain are expected as an Arctic blast moves south from Canada.

NPR's Rebecca Herscher says a polar vortex will linger after the snow stops falling.

Usually, freezing cold air is trapped up in the polar regions.

The jet stream keeps the cold air trapped up there.

But when the jet stream gets weaker, cold air can escape south,

deep into the continental U.S. That's what's expected to happen next week.

Scientists are actively trying to understand whether climate change makes such events more likely.

Some studies suggest the jet stream is getting weaker as the earth warms, while others find no such

relationship. What is clear is that polar vortex conditions can be deadly, especially in parts

of the country that aren't accustomed to very cold weather. Rebecca Herscher, NPR News.

The governors of more than a half dozen states have declared a state of emergency ahead of the

upcoming winter storm. They include Texas, Georgia, South Carolina, Tennessee, and Virginia.

Members of the National Guard are being mobilized in those states. President Trump's special

envoy, Steve Whitkoff, and Trump's son-in-law, Jared Kushner, have been meeting with Russian President Vladimir Putin today in Moscow.

The talks are the latest to try to end Russia's war with Ukraine.

Trump told reporters aboard Air Force One, Putin wants a deal.

We're discussing things that have been discussed for six or seven months and he came and he said he wants to

make a deal. The talks came hours after Ukraine's president, Volodomir Zelensky, criticized his

European allies for their response to Russia's full-scale invasion of Ukraine. President Trump is

...